Collapsible steering column assembly

ABSTRACT

A collapsing steering column assembly for an automotive vehicle, comprising an inner column tube, a steering shaft, a tilt bracket, and a steering wheel adjustment subassembly. During a secondary impact, at least a portion of the steering wheel adjustment subassembly is adapted to detach relative to the tilt bracket by way of at least one breakaway structure and translate (e.g., at least partially longitudinally) during the impact, such as a secondary impact, for moving away from a vehicle operator.

CLAIM OF PRIORITY

The present application claims the benefit of the filing date of U.S.Patent Application Nos. 61/886,788, filed Oct. 4, 2013; 61/888,323,filed Oct. 8, 2013; and 62/040,092, filed Aug. 21, 2014, all of whichare hereby incorporated by reference in their entirety.

FIELD

In general, the present teachings relate to an improved collapsiblesteering column assembly and methods associated with the same (e.g.,methods of providing energy absorption, such as in a secondary impact).More particularly, though having aspects making it adaptable to externalcollapsing column systems, the present teachings are directed mainly atan internal collapsing tilt and/or telescopically adjustable steeringcolumn system.

BACKGROUND

During a vehicle collision, there are commonly two impacts. In a primaryimpact, the vehicle impacts another object. In a secondary impact, avehicle occupant impacts a component of the vehicle. For example, avehicle operator sometimes impacts the steering wheel due to inertia. Inorder to help try to protect drivers from such secondary impacts, it hasbecome common practice to use an impact-absorbing type steering column.A collapsible steering column system is an example of animpact-absorbing type steering column.

The structure of an impact-absorbing type steering column apparatus issuch that when the driver suffers a secondary impact, the impact energyacts on the steering column in the frontward direction of the vehicle.The steering column may detach from one or more fixation points with thevehicle body and move forward (e.g., in a collapse stroke), so that theimpact energy is absorbed in the course of the collapse stroke. Anexternal collapsing column assembly is an example of a system in whichthe entire column will translate relative to its fixation points. Aninternal collapsing column assembly typically will be fixed at one ormore fixation points near one of the ends of the assembly within thevehicle. During a collapse stroke from a secondary impact, components ofthe assembly will longitudinally collapse (e.g., generally within thevolume it occupies within the vehicle in normal operation; that is,generally within its “footprint” in the vehicle), but generally will notcollapse beyond a certain distance relative to a predetermined fixationpoint. An internal collapsing system thus has a stroke, but may remainfixed to the vehicle at the one or more fixation points.

For many applications, steering column assemblies incorporate one orboth of a tilt or telescopic function. For these applications, it iscommon to employ levers for manual performance of such functions by avehicle user. By way of example, in what is known as a “manual rake andreach” steering column assembly, the assembly will have both a tilt(“rake”) and a telescopic (“reach”) function, with a lever provided fora vehicle user to manually release for affording rake and reachadjustment to a selected position, and then to re-engage for fixing thesteering column in the selected position.

Notwithstanding efforts to improve collapsible steering columnassemblies, (e.g., internally collapsible steering column assemblies),there remains a need for alternative assemblies, particularly those inwhich during an impact such as a secondary impact, one or both of a useroperating device (e.g., a lever) and a steering wheel (if employed) maybe translated forward and away from a vehicle user.

The following U.S. patent documents may be related to the presentinvention: Published U.S. Patent Application Nos. 2008/0236325;2008/0111363; 2009/0174177 2010/0300238; 2010/0032933; and U.S. Pat. No.8,047,096, all of which are incorporated by reference herein for allpurposes. Published U.S. Application No. 2013/0233117 also may haveteachings related to the present invention and is incorporated byreference herein.

SUMMARY

The present teachings make use of a simple, yet elegant, constructionapproach by which relatively few components can be employed forachieving an energy absorbing steering column assembly, such as acollapsible steering column assembly. The steering column assembly maybe an adjustable (e.g., for rake and/or reach) steering column assembly.For example, though having applicability to externally collapsingassemblies (which are contemplated within the present teachings), thesteering column assembly herein may be an internally collapsibleassembly. It may be an assembly that is affixed within a vehicle at oneor more fixation points so that upon a secondary impact the steeringcolumn assembly resists forward motion substantially beyond (e.g.,longer than about 20 mm or 10 mm beyond) the one or more fixationpoints. It may be a collapsible steering column assembly that exhibitsrelatively good energy absorption characteristics, especially during asecondary impact. It may be a collapsible steering column assembly thatexhibits longitudinal displacement (e.g., forward translation) of anadjustment lever (e.g., a lever for manual adjustment) during asecondary impact.

As one general way of characterizing the present teachings, there isenvisioned a collapsing steering column assembly. It may be aninternally collapsing assembly or an externally collapsing assembly.Though, it is particularly attractive for an internally collapsingassembly in which at least a portion of the assembly is secured againstany substantial forward movement (e.g., less than about 50 mm, 20 mm, or10 mm) within a vehicle. The steering column assembly may include asteering wheel position adjustment portion (e.g., an arrangement adaptedfor adjusting the rake and/or reach position of a steering wheelrelative to a vehicle operator, such as a telescoping tubulararrangement). It may include a bracket (e.g., a tilt bracket) for atleast partially carrying the steering wheel position adjustment portionand attaching the assembly within the vehicle. It may include a securingmember (e.g., as discussed elsewhere herein, a tilt bolt or otherelongated member, such as one that is adapted for applying a securingforce to help maintain a steering column assembly in a desired position)for fixing the position of the steering wheel position adjustmentportion (such as by operation of a lever that is adapted to be employedby an operator to apply or remove a securing force). It is envisionedthat the assembly may include a breakaway structure associated with thebracket, the securing member or both. For instance the breakawaystructure may be configured in a manner such that it can allowdisengagement of two or more components relative to each other so thatone or more components of the steering wheel adjustment portiontranslate forward in the event of an impact, such as a secondary impact.It is also envisioned that the assembly may include at least one energyabsorption device that is operable to absorb energy in a collapse strokeoccasioned in response to a force applied to it due to the secondaryimpact. For instance, forward travel may result for the securing memberas a result of the impact such as a secondary impact and as a result ofthe above mentioned disengagement; in a collapse stroke, the securingmember may thus apply a forward force that directly or indirectlyoperatively engages the at least one energy absorption device (e.g., aplastically deformable elongated member such as a metal strip or bendplate). It is seen that it is possible that the securing member may beconfigured relative to the breakaway structure in a manner such that inthe event of a secondary impact exceeding a threshold load, at least aportion of the securing member breaks away from a secure engagementposition by way of the breakaway structure and allows a portion (e.g.,an inner column tube) of the steering wheel adjustment portion totranslate forward (e.g., relative to a column housing that may bepivotally mounted and/or may be generally fixed in position to avoidforward travel in a collapse stroke) and simultaneously causes theenergy absorption device to deform and thereby absorb energy from thesecondary impact. The secure engagement position may be where at least aportion of the steering shaft support structure (e.g., an inner columntube, a column housing, or both) is fixed in a fixed position steeringcolumn assembly. The secure engagement position may be the adjustedposition selected by the user in an adjustable position steering columnassembly.

In one general aspect of the teachings, there is contemplated acollapsing steering column assembly that includes an inner column tube,a steering shaft (adapted for coupling with a steering wheel or otherlike structure) that is supported for rotation at least in part by theinner column tube and having a longitudinal axis; and a suitable bracketfor carrying the inner column tube and attaching the assembly within avehicle (e.g., to a cross-vehicle structure). The bracket may be coupledwith a column housing, such as for securing the column housing in agenerally fixed position within the vehicle. The inner column tube mayconfigured to be carried by the column housing (e.g., in a telescopingmanner), in one or more fixed positions. For example, the inner columntube may be telescopically adjustable (e.g., by way of a manualadjustment lever) within and/or relative to the column housing. Thecolumn housing and the inner column tube each will have a longitudinalaxis. Their respective longitudinal axes may be generally aligned (e.g.,they may be generally co-axial). The position of the inner column tuberelative to the column housing may be fixed by way of a securing member(e.g., a tilt bolt as will be described) that is located in a secureengagement position and applies a force (e.g., a generally transverseforce relative to the longitudinal axes of the inner column tube and thecolumn housing) to at least one of the column housing or inner columntube for causing a secure engagement of the inner column tube and thecolumn housing (e.g., a clamped engagement, an interference, interlock,detent or other mechanical engagement). The securing member may be suchthat in the event of a secondary impact exceeding a threshold load, thesecuring member breaks away from its secure engagement position andallows the inner column tube to translate (e.g., forward) relative tothe column housing. The securing member may be such that, in the eventof a secondary impact exceeding a threshold load, as the securing memberbreaks away from its secure engagement position and allows the innercolumn tube to translate (e.g., forward) relative to the column housing,it also causes an energy absorption device (e.g., a metal strip) toabsorb energy from the secondary impact (e.g., by plastically deforming(with or without elongation, compaction, shear strain, and/orbuckling)).

With reference to one illustrative example, as will be seen herein, thepresent teachings relate to a collapsing steering column assembly (e.g.,an internally collapsing steering column assembly) for an automotivevehicle, including an inner column tube; a steering shaft supported forrotation at least in part by the inner column tube and having alongitudinal axis; and a bracket (e.g., a tilt bracket adapted forreceiving or otherwise carrying and/or supporting at least a portion ofthe inner column tube and/or for mounting the steering column assemblywithin the automotive vehicle). A column housing may be employed fortelescopically carrying the inner column tube (e.g., the inner columntube may be configured to be located within the column housing). Thecolumn housing and inner column tube may be part of a steering shaftsupport structure. The column housing may have a portion that is adaptedto be pivotally mounted within a vehicle (e.g., in a fixed position, orin a position that allows slight forward travel (e.g., about 20 mm orabout 10 mm) of the column housing from a load occasioned by a secondaryimpact). The bracket (e.g., tilt bracket) may include at least oneportion adapted to mount the assembly to a vehicle (e.g., to across-vehicle structure), and a portion adapted to carry (directly orindirectly) the inner column tube. For example, the bracket may includean upper wall for attachment to the vehicle and an outwardly projectingwall structure that projects away from the upper wall (and which may beconfigured to flank the inner column tube and/or afford at least apartial vertical translation of the inner column tube relative to theupper wall). A manually operated steering wheel adjustment subassemblymay also be employed. It may be adapted for (i) selectively adjustingthe steering shaft in a fore or aft direction generally along thelongitudinal axis, (ii) selectively raising or lowering the steeringshaft; or (iii) both (i) and (ii). The steering wheel adjustmentsubassembly typically will include a lever adapted for manuallyactuating the subassembly, and at least one engagement member that isbrought into and out of engagement with the inner column tube forselectively locking the steering shaft into a position (which may berelative to the position of the column housing) desired by a user. It isenvisioned that there may be a suitable breakaway mechanism (e.g., atleast one breakaway insert, or another suitable structure for causingdisengagement of the inner column tube from a fixed position selected bythe user so that it can travel forward relative to the tilt bracket)that detachably mounts the steering wheel adjustment subassemblyrelative to the tilt bracket. A fastener assembly may operativelyconnect the lever, the engagement member, and the at least one breakawaymechanism. The column housing may be pivotally mounted at a pivotmounting location within the automotive vehicle. The column housing mayat least partially surround the inner column tube. The column housingmay be in clamping relation with the inner column tube so as to permitsteering shaft adjustment by way of the steering wheel adjustmentsubassembly. The column housing, the tilt bracket, and/or the innercolumn tube may thus include a structure adapted for clamping the columntube into position using the lever. Desirably, during a secondaryimpact, the column housing remains in a generally fixed positionrelative to the pivot mounting location (e.g., if it travelslongitudinally it travels less than about 20 mm or 10 mm); and (a) atleast a portion of the steering wheel adjustment subassembly detachesfrom or otherwise becomes displaced relative to the tilt bracket by wayof the at least one breakaway insert and translates longitudinallyduring the secondary impact for moving the lever away from the user;and/or (b) upon longitudinal translation of the at least one breakawayinsert, the inner column tube becomes unclamped relative to the columnhousing, the tilt bracket, or both.

By way of summary, in yet one additional illustrative example, theteachings herein contemplate an internally collapsing steering columnassembly for an automotive vehicle, comprising: a.) an inner columntube; b). a steering shaft supported for rotation at least in part bythe inner column tube and having a longitudinal axis; c.) a tilt bracketadapted for receiving at least a portion of the inner column tube andfor mounting the steering column assembly within the automotive vehicle,the tilt bracket including a wall structure that at least partiallyflanks the inner column tube (e.g., a pair of opposing side walls); d.)a manually operated steering wheel adjustment subassembly adapted for(i) selectively adjusting the steering shaft in a fore or aft directiongenerally along the longitudinal axis, (ii) selectively raising orlowering the steering shaft; or (iii) both (i) and (ii). The steeringwheel adjustment subassembly includes a lever adapted for manuallyactuating the subassembly, at least one engagement member that isbrought into and out of engagement with the inner column tube forselectively locking the steering shaft into a position desired by a user(e.g., fore or aft), at least one breakaway insert that detachablymounts the steering wheel adjustment subassembly relative to the tiltbracket (e.g., directly to the tilt bracket), and a fastener assembly(such as one that includes at least one fastener such as a tilt bolt)that operatively connects the lever, the engagement member and thebreakaway insert. A column housing is pivotally mounted at a pivotmounting location within the automotive vehicle and at least partiallysurrounds the inner column tube in a relation that may be adapted forclamping or unclamping with the inner column tube (e.g., when the leveris in a predetermined position) so as to permit steering shaft tiltadjustment by way of the steering wheel adjustment subassembly. Thecolumn housing may include a suitable structure for releasably clampingor otherwise engaging the inner column tube into position. For instance,it may include an elongated longitudinally oriented opening that definesan inner surface structure that may include opposing inner surfaces(e.g., wall surfaces) that can be urged toward the inner column tube forclamping the inner column tube into position, e.g., by using the leverto apply a clamping force, such as by way of the tilt bracket. During animpact such as a secondary impact, the column housing remains in agenerally fixed position relative to the pivot mounting location.Further, at least a portion of the steering wheel adjustment subassemblymay be adapted to detach from the tilt bracket, such as by way of the atleast one breakaway insert and translate (e.g., at least partiallylongitudinally) during the secondary impact for moving the lever awayfrom the user. During detachment (e.g., during breakaway of thebreakaway insert), the inner structure of the column housing allows theinner column tube to move forward relative to the column housing. Aninner wall structure of the column housing, the tilt bracket, or both,may open relative to the inner column tube to allow forward motionrelative to the column housing. For example, inner wall surfaces of thecolumn housing are such that they spread apart from each other (e.g.,due to residual internal stress), thereby allowing the inner column tubeto move forward relative to the column housing.

The teachings herein also contemplate methods. For example, theteachings envision a method of managing energy distribution andcontrolling adjustment lever disposition resulting from a secondaryimpact of a vehicle occupant by using an automotive vehicle steeringcolumn assembly as described in the above, and as set forth morespecifically in the following teachings.

As can be gathered from the description herein, the teachings envisionin one or any combination of the following general aspects, a steeringcolumn assembly by which (i) a securing member (e.g., a tilt bolt) maydisengage from at least a portion of a bracket (e.g., a tilt bracket) inthe event of an impact such as a secondary impact; (ii) a column housingmay unclamp or otherwise become disengaged from an inner column tube inthe event of a secondary impact; (iii) an energy absorption device maybe engaged and actuated in the event of an impact such as a secondaryimpact and helps to absorb energy from the impact; (iv) a securingmember may apply a force to an energy absorption device during an impactsuch as a secondary impact as the securing member travels forward (e.g.,upon disengagement from at least a portion of a bracket (e.g., a tiltbracket); (v) a lever associated with a manually actuated steeringcolumn assembly (e.g., for actuating rake and/or reach functions) maytranslate forward in the event of an impact such as a secondary impact;(vi) a lever associated with a manually actuated steering columnassembly (e.g., for actuating rake and/or reach functions) may translateforward in the event of an impact such as a secondary impact and maycarry only a portion or no portion of a bracket (e.g., a tilt bracket)with it; (vii) the structure is adaptable for an internally collapsingsteering column assembly or an externally collapsing steering columnassembly; (viii) in lieu of a lever actuating, there can be substitutedanother position locking actuator (e.g., an electromechanical switch);or (ix) at least a portion of the bracket (e.g., the tilt bracket)remains in its original fixed position in a vehicle following secondaryimpact; (x) for an internally collapsing system, the original pivotlocation remains the same as the resulting pivot location following animpact such as a secondary impact; or (xi) in the event of an impactsuch as a secondary impact, and upon disengagement of a securing memberrelative to at least a portion of a bracket, a forward travel of thesecuring member causes unclamping or other disengagement of a columnhousing relative to an inner column tube.

As can be seen, it is thus possible to realize a unique assembly (andassociated methods) that enable a steering column assembly to transmitsteering torque, smoothly rotate, and absorb energy during an impactsuch as a secondary impact during a vehicle collision, while alsoproviding adjustable driving positions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative assembly in accordancewith the present teachings viewed from the bottom.

FIG. 2 is an exploded perspective view of the assembly of FIG. 1.

FIG. 3 is a perspective view of an illustrative breakaway insert inaccordance with the present teachings.

FIG. 4 is a perspective view of an illustrative spacer in accordancewith the present teachings.

FIG. 5 is a perspective view of an illustrative plate stop in accordancewith the present teachings.

FIG. 6a is an enlarged perspective view illustrating use of anillustrative breakaway insert, such as that of FIG. 3.

FIG. 6b is an enlarged perspective view illustrating use of anillustrative spacer, such as that of FIG. 4.

FIG. 7a is a side view of an assembly in a normal operational mode.

FIG. 7b is an illustrative side view of the assembly of FIG. 7a after acollapse stroke has occurred.

FIG. 8a is an illustrative bottom view of an assembly in a normaloperational mode.

FIG. 8b is an illustrative bottom view of the assembly of FIG. 8a aftera collapse stroke has occurred.

FIG. 9a is a side view of an illustrative bracket.

FIG. 9b is a side view of another illustrative bracket.

DETAILED DESCRIPTION

As required, detailed embodiments of the present teachings are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the teachings that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present teachings.

In general, and as will be appreciated from the description thatfollows, the present teachings pertain to a collapsing steering columnassembly. The steering column assembly may include a mounting portionfor securing the steering column assembly in a vehicle in a fixedoperational position. The assembly may have a collapsing portion, atleast a portion of which is adapted to travel forward relative to themounting portion, while the mounting portion stays generally in itsfixed operational position (e.g., any travel of the mounting portion iscontrolled and limited to an amount of less than about 50 mm, 20 mm oreven 10 mm). Among its basic concepts the teachings are directed to asteering column assembly that, in the event of an impact such as asecondary impact that results in a load of a certain threshold amount(e.g., a load of about 0.5 kN or more or about 2 kN or more; a load ofabout 10 kN or less or about 5 kN or less), may be adapted so that atleast a portion of the collapsing portion travels forward within thevehicle. The forward travel may be in a telescopic manner (e.g., atleast one first structure that is operatively connected to a steeringwheel (such as an inner column tube) may advance forward (e.g., along anaxis that is generally parallel with (such as within about 10° of beingparallel with) a vehicle longitudinal axis) in a vehicle relative to atleast one second structure that may at least partially surround the atleast one first structure (e.g., a column housing)). As will be alsoseen, the teachings envision that the steering column assembly mayinclude a tilt or rake adjustment that is adapted to allow a user toselect an angle of inclination of a steering wheel, a reach adjustmentthat is adapted to allow a user to select an appropriate fore-aftposition of the steering wheel, or both. In general, any such adjustmentmay be controlled by a suitable user operating device (e.g., a lever, anelectromechanical actuator, or otherwise). For a manually operatedsystem, a lever or other user operating device may be adapted to controla force applied to maintain the collapsing portion in a user selectedposition. For example, a lever or other user operating device may be inoperative engagement with one, two, or more clamping portions or othersuitable mechanism to releasably (and possibly adjustably as well)secure two or more components of the collapsing portion together.Clamping or other securing may be realized by a suitable securing member(e.g., an elongated force applying member), such as a bolt (e.g., a tiltbolt), rod, strap, bar, band, wedge, or other suitable member. Forinstance, the securing member may be adapted, upon actuation of the useroperating device to cause generally opposing portions (e.g., clampingportions) to separate or come closer together such as, respectively, forreleasing the components relative to each other or for securing thecomponents relative to each other.

The securing member is held in a fixed position within the steeringcolumn assembly during normal vehicle operation. In the event of animpact such as a secondary impact, it is envisioned that some or all ofthe securing member may disengage from the fixed position and travelforward in the vehicle. For example, the securing member may beconfigured for allowing it to rupture, plastically deform, or cause someother structure (e.g., a portion of the collapsing portion and/ormounting portion, such as a mounting arm) to rupture or plasticallydeform upon realization of a predetermined load. In this manner, it maybe possible that the securing member releases any force being applied tosecure components of the collapsing portion together, so that collapseis possible. It may be possible as well that the securing member may beconnected with a user operating device (e.g., a lever). Forward movementof the securing member thus may also cause the user operating device totravel forward as well.

As noted, the bracket structures (e.g., tilt brackets) of the teachingsherein can be modified to provide a breakaway structure. A bracket mayinclude an upper wall and projecting side walls (e.g., including anelongated slot for tilt adjustment) as previously described. Instead ofa breakaway insert, the side walls may be configured to define one ormore stress concentrators. Thus in the event of an impact such as asecondary impact, an elongated fastener or other securing member (e.g.,tilt bolt) may cause a portion of one or both of the side walls torupture so that breakaway can occur. For example, a notch defining athinned portion may be employed. The side wall structure (e.g., aforward or a rearward portion of the sidewall structure) may thus bestructured to allow a portion of the side wall (e.g., a lower portion,an upper portion, a forward portion and/or a rearward portion) to breakaway from another fixed portion (e.g., respectively, an upper portion, alower portion, a rearward portion and/or a forward portion). Theelongated fastener or other securing member may thus be retained in thebroken away portion. The elongated fastener or other securing member maybreak through a portion of the side wall. By way of example, a thinnedforward wall section in one or both side walls may be defined as aresult of a notch from a rear portion of the side wall. A thinnedforward section of one or both sidewalls may be employed. One or moreoptional notches may be employed in a forward facing portion of one orboth side walls. One or more of such a notch or some other suitablestructure may assist in defining one or more stress concentrators forhelping to control rupture of the forward portion of the side wall forallowing the elongated fastener or other securing member to break awayfrom the bracket (either carrying a portion of one or both side walls ornot). Any combination of the above features may be employed.

The teachings, in general, also envision the possible use of one or moreenergy absorption devices. The energy absorption devices may be asuitable device adapted to deform elastically and/or elastically andplastically. In the course of deforming, the energy absorption devicesare thus adapted to absorb energy by way of the deformation. The energyabsorption device may be operatively connected or located between oramong two or more components. It may be configured so that it limitsrelative movement as between or among two or more components. The energyabsorption devices may be wires, plates or the like. They may have aconstant profile or a varying profile along their length. They may beemployed to have one or more fixedly constrained portions (e.g., anend). They may have one or more free ends.

As the above indicates, there are many unique features associated withthe present teachings. It is possible, in the event of an impact such asa secondary impact, for at least a portion (if not all) of the securingmember to break away from its normal operating position (e.g., a secureengagement position). It is possible, in the event of a secondaryimpact, for at least a portion (if not all) of the securing member totravel at least a portion, if not the full extent, of a strokeoccasioned by the impact. It is possible, in the event of an impact suchas a secondary impact, for at least a portion (if not all) of thesecuring member to break away from its normal operating position andcause a release of a force (e.g., it releases one, two or more clampingportions) as between or among two or more components, so that the two ormore components can move (e.g., in a defined manner) relative to eachother (e.g., an inner column tube can move forward within (such astelescopically) or otherwise relative to a column housing). It ispossible, in the event of an impact such as a secondary impact, for atleast a portion (if not all) of the securing member to break away fromits normal operating position. It is possible to employ the teachingsherein with an internally collapsing steering column assembly, thoughthe teachings are not limited to such category of steering columnassembly. For instance, the teachings herein may employ an arrangementby which the collapsing portion includes a column housing that is fixedfor no forward movement upon an impact such as a secondary impact in alocation within the vehicle (e.g., it may be pivotally fixed within avehicle). The teachings herein may employ an arrangement by which thecollapsing portion includes a column housing that is fixed forrelatively slight forward movement within the vehicle (e.g., it may bepivotally fixed within a vehicle and adapted to travel forward by anamount less than about 50 mm, 20 mm or 10 mm in the event of an impactsuch as a secondary impact).

As noted, one of the features herein relates to the ability, in theevent of an impact such as a secondary impact, for at least a portion(if not all) of the securing member to break away from its normaloperating position. In Illustrative embodiments described in thefollowing, it will be seen that one approach is to employ a lever orother user operating device that applies a securing force (e.g., by wayof an elongated fastener such as tilt bolt or other securing member) toactuate hardware of a subassembly for causing clamping or unclamping (orsome other engagement/disengagement) of the column housing to the innercolumn tube. Though the breakaway function is described as beingachieved by use of a breakaway insert that cooperates with a tiltbracket, other structural arrangements are possible as well. By way ofexample, without limitation, other structures that may be employed as analternative to, or in addition with, the breakaway insert of the presentteachings include the use of locally weakened portions of side walls ofa bracket such as a tilt bracket (e.g., a locally weakened portion, suchas by use of a relatively thin wall, a wall with one or morepredetermined stress concentrators, material choice, any combinationthereof or otherwise). This may be in the form of a forward facing edgeportion of a bracket that adjoins an elongated slot, such as a tiltguide slot. It may be in a form of a relatively thin neck that connectsone or more side walls of the bracket to an upper portion. Uponrealization of a predetermined threshold load from an impact such as asecondary impact, the locally weakened portions may rupture, shearand/or deform in response to a load, so that it releases forces appliedto secure two or more components together, and thereby allow at leastone of the components to travel relative to another.

A locally weakened securing member (e.g., an elongated fastener such asa tilt bolt) may be selectively weakened (e.g., by material choice, bystress concentration design (e.g., inclusion of a selectively thinnedsection in a region where stress concentration is desired), or both). Inthis manner it may rupture, shear and/or deform in response to a load,so that it releases forces applied to secure two or more componentstogether, and thereby allows at least one of the components to travelrelative to another. Any combination of the above can be employed aswell.

In examples illustrated, teachings describe aspects useful for aninternally collapsing steering column assembly for an automotivevehicle. In general, an assembly of the teachings herein may include asteering shaft (e.g., one that can be coupled with a steering wheel orother steering device) and/or an inner column tube that supports thesteering shaft (e.g., via one or more bearings). A column housing may beemployed. It may be adapted to telescopically couple with the innercolumn tube (e.g., each may have a longitudinal axis that is generallyparallel or even coaxial with each other). A bracket may be employed forat least partially securing either or both of the inner column tube orthe column housing to the vehicle (e.g., to a cross-vehicle structure).The bracket may include a suitable portion (e.g., a slot such as agenerally vertically oriented slot) adapted to provide a guide structurefor a tilt function. A user operating device, such as a lever, may beemployed for allowing a user to manually operate the assembly. Anelectromechanical device that applies or releases a force in response toa signal from an operation switch may be employed. The lever or otheruser operating device may be such that, depending upon its position, itcauses clamping of the inner column housing relative to the inner columntube. The lever or other user operating device may be such that,depending upon its position, it causes an engagement or disengagement(e.g., clamping or unclamping) of the column housing relative to theinner column tube. The lever or other user operating device may beassociated with a steering wheel adjustment subassembly and configuredso that in the event of a threshold load realized during an impact suchas a secondary impact, at least a portion the subassembly is able tobreak away from its typical operational position. As a result of thebreakaway, the lever or possibly at least a portion of the useroperating device may thus be able to travel forward, e.g., away from theuser. As a result of the breakaway the inner column tube may thus berendered able to translate forward relative to the column housing,carrying with it the steering wheel attached. As a result, it can beseen that it is possible that one or both of the lever (or possibly anelectromechanical actuator or some other portion of the user operatingdevice), or the steering wheel is rendered able to translate forward,e.g., away from the user.

With reference now to more particular examples of suitable structures ofthe present teachings, it can be seen that the teachings address anassembly that may typically include an inner column tube, a steeringshaft, a bracket (e.g., a tilt bracket), a column housing, and asteering wheel adjustment subassembly (e.g., a manually operatedsteering wheel adjustment subassembly). The steering wheel adjustmentsubassembly may include a lever (as discussed, or some other useroperating device) adapted for actuating (e.g., manually actuating) thesubassembly, and at least one engagement member that is brought into andout of engagement with the inner column tube for selectively locking thesteering shaft into a position desired by a user. A mounting structuremay detachably mount the steering wheel adjustment subassembly relativeto the bracket (e.g., tilt bracket). At least one structure configuredto allow for breakaway of at least a portion of the steering wheeladjustment subassembly relative to a fixed component of the assembly maybe employed. For example, at least one breakaway insert may detachablymount the steering wheel adjustment subassembly to the bracket (e.g.,tilt bracket). A fastener assembly operatively connects the lever, theengagement member and the breakaway insert. During an impact such as asecondary impact, the column housing remains in a generally fixedposition relative to a forward pivot mounting location (e.g., anyforward translation is limited to a relatively small amount (e.g., about20 mm or 10 mm)). Further, at least a portion of the steering wheeladjustment subassembly (e.g., suitable mounting structure) is adapted todetach from or otherwise become translated relative to the bracket(e.g., tilt bracket) by way of the at least one breakaway structure(e.g., breakaway insert) and translate (e.g., at least partiallylongitudinally) during the impact such as a secondary impact for movingthe lever away from the user. In this manner, it is also envisioned thatthe inner column tube may become un-clamped or otherwise disengaged andtranslated forward relative to the column housing, the bracket (e.g.,tilt bracket), or both.

With more attention now to the details of the assemblies herein, theygenerally will include a tube that is operatively connected with asteering wheel (not shown), e.g., via a steering shaft. One such tube,referred to herein as an inner column tube, typically will have a hollowcavity along at least a portion of (if not the entirety of) the lengthof the tube and may be sized and configured to receive and support arotatable shaft, namely a steering shaft and possibly one or morebearings. Both the shaft and the tube will have a longitudinal axis.When installed in a vehicle, the longitudinal axis of each the shaft andthe tube (as well as the steering column assembly in general) may begenerally coaxially aligned, aligned generally parallel with alongitudinal axis of a vehicle, or each. The shaft and the Inner columntube typically will be made of or otherwise include a suitable metal,such as one or more of iron (e.g., steel), magnesium, zinc, or aluminum.

The inner column tube may be generally cylindrical and hollow. It mayhave a forward end portion and a rearward end portion, and alongitudinal axis. Either or both of the forward or rearward end portionmay include a suitable bearing that supports the steering shaft forrotation.

The steering shaft may have a rearward end portion adapted to receive asteering wheel (not shown). It may have a forward end portion thatpenetrates through and may be supported by a bearing, a key lock collaror both. As noted, the steering shaft may be supported for rotation atleast in part by the inner column tube and have a longitudinal axis thatmay be generally coaxially aligned with the longitudinal axis of theinner column tube.

One or more suitable brackets may be employed. Any such bracket mayinclude a portion for mounting the steering column assembly within avehicle (e.g., it can be secured to a vehicle structure, such as a crossvehicle beam, instrument panel, or otherwise). The bracket may have aportion that at least partially adjoins the steering shaft supportstructure (e.g., the inner column tube, the column housing or both). Forexample, it may include one or a plurality of downward depending(downwardly oriented) walls that define a tilt portion of the bracket.One or more of the downward depending walls may be adapted to provide astructure that has an elongated slot that provides guidance for the tiltfunction (e.g., it provides a guide path for a securing member such as atilt bolt as it travels during adjustment; it may thus limit upward anddownward travel). The bracket may be an integrated structure so that thetilt portion and the mounting portion are a single structure (e.g., acasting, a stamping, or a combination thereof). The bracket may be madeof separate structures that are assembled together to define themounting and tilt portions in a single structure. The mounting portionmay be omitted. The tilt portion may be omitted. A mounting bracket maybe employed separately from a structure defining a tilt portion.Examples of brackets that may be employed, in addition to the examplesdescribed herein, include those of United States Published ApplicationNo. 20100300238 (the entirety of which is incorporated by reference forall purposes; see, e.g., description of bracket 20); U.S. Pat. No.6,467,807, the entirety of which is incorporated by reference for allpurposes (see, e.g., description of brackets 6 and 7 and associatedstructure).

One or more brackets (e.g., tilt brackets) may be employed and adaptedfor receiving at least a portion of a steering shaft support structure(e.g., at least a portion of the inner column tube, the column housing,or both), and/or for mounting the steering column assembly within theautomotive vehicle. By way of example, a tilt bracket of the presentteachings may include an upper portion that is adapted to be secured toa vehicle structure, such as a cross vehicle beam, instrument panel, orotherwise. The bracket (e.g., tilt bracket) may have a pair of generallyopposing downwardly oriented or projecting walls. The bracket (e.g.,tilt bracket) may have a structure that at least partially flanks atleast a portion of the steering shaft support structure (e.g., the innercolumn tube). The bracket (e.g., tilt bracket) may include a pair ofopposing side walls, and an upper wall that is configured to attach tothe vehicle (e.g., to a cross vehicle beam, an instrument panel, orother suitable structure). The side walls may project outward relativeto the upper wall (e.g., they may be generally orthogonally or obliquelydisposed relative to the upper wall). The bracket (e.g., tilt bracket)may have a single downwardly projecting or oriented wall. The bracket(e.g., tilt bracket) may be disposed laterally above and outwardrelative to an opposing portion of the column housing.

For teachings that employ an illustrative breakaway insert as describedherein, one or more of the side walls may have one or more cut-outs,e.g., generally c-shaped cut-outs. The cut-outs may open from agenerally forward direction of the side walls (e.g. forward facingcut-out). One or more surfaces that define the cut-outs may be taperedin a longitudinal direction. The tilt bracket may be a cast structure(e.g., a casting containing aluminum, magnesium, or steel). The sidewalls may also include one or more elongated guide slots to provide astructure that allows components of the steering column assembly to beguided while being raised or lowered. For example, the side walls mayhave a forward facing edge that is downwardly oriented. A forward wallthat defines the elongated guide slot may be spaced from the forwardfacing edge by a distance that enables the side wall to rupture upon apredetermined load from a secondary impact. The side walls may have arelatively thin neck that connects one or more side walls of the bracketto an upper portion. The neck thickness may be sufficiently sized toenable tilt adjustment and securing in a fixed position while resistingforward forces normally encountered from an operator while operating avehicle and making column adjustments. It may be sufficiently thin thatin the event of a load encountered during an impact such as a secondaryimpact from a collision, the neck will rupture to allow breaking away inaccordance with the teachings herein.

It is possible that the teachings herein can be employed for steeringcolumn assemblies that are not adjustable, but which still require theability to collapse. In such instances, there will be no rake or reachadjustment hardware. However, the concepts herein may still be adaptedto achieve collapse. A mounting bracket may secure one or both of acolumn housing, or an inner column tube, to a vehicle. For example, amounting bracket can incorporate a breakaway insert or other breakawayfeature as taught herein on one or more of its side walls for allowingforward travel upon a threshold load from an impact such as a secondaryimpact. Hardware for securing the steering column assembly to themounting bracket may be adapted to rupture or otherwise break away fromthe mounting bracket. An energy absorption device may be employed tolimit forward travel. Other variations will be apparent from theteachings herein, and breakaway features of the various embodimentsherein may be used for this embodiment.

The present teachings, however, have particular applicability forsteering column assemblies that are adjustable (e.g., for rake and/orreach). The assembly may include a manually operated steering wheeladjustment subassembly adapted for selectively adjusting the steeringshaft in a fore or aft direction generally along the longitudinal axis,selectively raising or lowering the steering shaft, or both. Thesteering wheel adjustment subassembly may include a lever or otheradapted for manually actuating the subassembly. The subassembly mayinclude at least one engagement member that is brought into and out ofengagement with the inner column tube for selectively locking thesteering shaft into a position desired by a user (e.g., a fore or aftposition). The subassembly may include at least one breakaway insertthat detachably mounts the steering wheel adjustment subassembly to thetilt bracket. The subassembly may include a fastener assembly (e.g., onethat includes at least one fastener, which may be referred to as a tiltbolt) that operatively connects the lever, the engagement member, andthe breakaway insert. Other suitable hardware may be employed in thesubassembly, such as one or more thrust bearings, one or more nuts, oneor more cam fix elements, and/or one or more cam move elements (e.g.,where the cam fix and the cam move elements are in opposing operativerelationship with each other, such as by contacting each other). Thesubassembly may also include one or more spacers as described furtherherein.

A column housing is pivotally mounted at a pivot mounting location(e.g., a permanently fixed mounting) within the automotive vehicle. Thepivot mounting location may be at or within about 20, 30, 40 or 50 mm ofa forward end of the column housing. The pivot mounting location may beon an underside of the column housing, on a top side of the columnhousing, or at some location in between the topside and the underside ofthe column housing. The column housing at least partially surrounds theinner column tube, and may be in clamping relation with the inner columntube when the lever or other user operating device is in a desiredposition so as to permit steering shaft adjustment (rake and/or reach)by way of the steering wheel adjustment subassembly. The column housingmay include a suitable clamping structure (e.g., two or more clampingportions (such as those shown as elements 12a and 12b in U.S. Pat. No.6,467,807, incorporated by reference for all purposes)). For instance,it may include an elongated longitudinally oriented opening that definesopposing inner wall surfaces that are urged toward the inner column tubefor clamping the column tube into position (e.g., by use of the lever toactuate hardware of the subassembly, such as the cam fix, cam moveelements, and/or thrust bearing). The column housing may have one ormore projections or other structure to receive a biasing device (e.g., aspring) that connects the column housing with the tilt bracket. Thecolumn housing may be a cast structure (e.g., including a metal such asaluminum, magnesium, zinc, and/or iron (e.g., steel)).

Examples of suitable column housing structures and arrangements can befound in U.S. Pat. No. 6,467,807 (referred to as “outer column”), theentirety of which is incorporated by reference for all purposes. Thecolumn housing may include clamping portions (such as those shown aselements 12a and 12b in U.S. Pat. No. 6,467,807). The clamping portionsmay face upwardly (e.g., as in embodiments of FIGS. 3, 5A-C, 6A-C, 7,and 11 of U.S. Pat. No. 6,467,807). The clamping portions may facedownwardly (e.g., as in embodiment of FIG. 14 of U.S. Pat. No.6,467,807). See also, United States Published Application No.20100300238, the entirety of which is incorporated by reference for allpurposes.

Clamping may be realized by way of a force from the steering wheeladjustment subassembly exerted by the lever or other user operatingdevice to cause the column housing to compress around the inner columntube. The force may be applied by way of the side walls of the bracket(e.g., of the tilt bracket), whether by way of by way of any breakawayinsert as described herein or not. It is also possible that a columnhousing is omitted, and/or in lieu of applying force to cause clampingportions of the column housing to compress and engage the inner columntube, force is applied directly by way of the bracket side wall (andpossibly indirectly by way of any breakaway insert as described herein).

As will become further apparent with reference to the drawings, during asecondary impact, the column housing may remain in a generally fixedposition relative to the pivot mounting location. It may be secured insuch a way that it translates forward a relatively small amount (e.g.,less than about 50 mm, 20 mm, or 10 mm).

During an impact (such as a secondary impact), the structures of thepresent teaching may be configured to include a suitable combination ofelements arranged in a manner so that an elongated fastener such as atilt bolt or other securing member, which may be operatively coupledwith a lever or other user operating device is able to translatelongitudinally and disengage from structure to which it is secured whenin a clamped position. For example, the elongated fastener (such as atilt bolt) or other securing member effectively may break away from sidewalls of a bracket (e.g., side walls of a tilt bracket). In one exampleillustrated herein, a suitable mounting structure (namely, one thatincludes at least one breakaway insert) is adapted to detach from thetilt bracket, such as by way of the at least one breakaway insert andtranslate longitudinally during the secondary impact for moving thelever away from the user. As seen, a clamping force that clamps thecolumn housing relative to the inner column tube (e.g., via the sidewalls of the column housing) may be released, thereby allowing the innercolumn tube to translate relative to the column housing.

The assembly herein may further employ an energy absorption structure ofthe type described in Published U.S. Application 2013/0233117, theentirety of which is incorporated by reference herein for all purposes.For instance the assembly herein may include at least one plasticallydeformable energy absorption device (e.g., a bend plate, a wire, or someother structure adapted to be carried at least partially by the columnhousing), wherein the energy absorption device, when employed, absorbsenergy by plastic deformation during the secondary impact after thesubassembly starts to translate along the column housing. Anyplastically deformable energy absorption device may thus limit theextent of longitudinal travel of the securing member. In an illustrationof the present teachings, a breakaway insert may be employed as astructure that allows the securing member to become disengaged from abracket (e.g., a tilt bracket). The breakaway insert may be configuredto complement the structure of the bracket (e.g., tilt bracket). It mayhave a length (such as from its forward-most point to its rearward-mostpoint). It may include a tapered portion that tapers from a forwardportion toward a rearward portion of the insert. It may include anelongated slot (e.g., in a rearward portion of the insert) adapted toreceive a fastener of the fastener assembly (or some other securingmember), such as a tilt bolt, and allow upward and downward motion ofthe steering shaft relative to the bracket (e.g., tilt bracket).Desirably, during normal operation, the tapered portion of the breakawayinsert contacts an opposing surface of the bracket (e.g., tilt bracket)and the dimensions of either or both of the taper of the tapered portionor the opposing surface are such that as the impact such as a secondaryimpact occurs, the breakaway insert is able to detach from at least aportion of the steering shaft support structure (e.g., column housing),at least a portion of the securing member that breaks away, or both totranslate forward. It will be appreciated that the taper can be omittedfrom the breakaway device and instead located only on the tilt bracket,or vice versa.

The engagement member may be a spring biased cam device. The engagementmember may optionally include teeth, which may be adapted to engage theinner column tube. A user operating device, such as a lever, may operatea cam locking system to apply clamp pressure. For instance, theengagement may be such that it occurs (e.g., via cam teeth) during animpact such as a secondary impact as the inner column tube starts tomove forward. Such engagement may in turn help initiate when breakawaystarts to occur. The engagement member may also be such that when a tiltlever is released, the engagement member rotates and does not touch theinner column tube so the steering wheel can be adjusted, and when thetilt lever is in a lock position the engagement member (e.g., via camteeth) may be in contact with the inner column tube.

The assembly may also include a longitudinally slotted plate stop deviceattached to the inner column tube. The longitudinally slotted plate stopdevice may be disposed in an elongated opening of the column housing andmay be configured to be fastened or otherwise attached to the innercolumn tube. The longitudinally slotted plate stop device may includeone or more base portions at each of its forward and rearward endportions. It may include opposing side walls that project upward fromthe one or more base portions. It may include longitudinally extendingside slots adapted to receive the fastener or other securing member. Itmay include at least one transversely extending flange on one or more ofthe side walls. It may include one or more elastic stoppers at terminallocations of the longitudinally extending side slots. It may include anupper longitudinal slot adapted to receive the engagement member. As canbe appreciated from the teachings herein, with reference to theillustrative embodiments, the plate stop device may be adapted to guideand/or restrict the travel of the fastener or other securing member asthe fastener or other securing member travels forward during a secondaryimpact.

As can be seen, the fastener or other securing member may be elongated.It may be at least partially surrounded by at least one spacer. Thefastener or other securing member may be at least partially surroundedby a hollow generally cylindrical spacer that has a first portionadapted to oppose any energy absorption device, such as an energyabsorption plate, and allow for sliding engagement with any such plateduring the secondary impact. The spacer may have a second portion thatincludes one or more projections adapted to be received within the tiltbracket, the column housing, or both, and that may be able to shearduring the secondary impact to allow the fastener or other securingmember to translate forward. For instance, the projection may be onopposing sides of the spacer. The projections may be located offsetrelative to a longitudinal axis of the spacer. The projections may havea height (relative to an enlarged head of the spacer) of about 1 toabout 5 mm. The projections may have a width of about 1 to about 5 mm.The projections may be taller than they are wide, or vice versa. Theymay have a width that is about the same as its height. The spacer may bedimensioned or configured so that at least a portion of it is disposedbeneath a portion of the slotted stop plate device for resisting columnlash.

As can be appreciated from the above, in the event of an impactoccasioning a collapse stroke, the breakaway insert or other breakawaystructure may result in a detachment of the securing member (e.g. afastener such as a tilt bolt) relative to the tilt bracket, the columnhousing and/or other side walls of a bracket or other structure. Duringthe collapse stroke, the fastener (such as a tilt bolt) or othersecuring member (e.g., a structure that carries the lever or other useroperating device) will be caused to translate forward, away from theuser. The fastener (such as a tilt bolt) or other securing member mayfollow a guided travel path, such as a path defined by the plate stopdevice. In addition, to the extent that an energy absorption device isused (e.g., bend plates), they will help absorb energy, typically byplastic deformation (e.g., as they unwrap around the spacer, such aswhile being carried on the column housing). For example, one or morebend plates may be at least partially wrapped around a portion of thefastener (e.g., tilt bolt) or other securing member. The one or morebend plates may be secured at some point along its length (e.g.,generally toward an end of the bend plate) to a fixed structure of thesteering column assembly (e.g., the tilt bracket, the column housing orotherwise). As the fastener or other securing member travels forward,the fixation will constrain a portion while another portion (e.g., aforward oriented portion) will bear against the fastener or othersecuring member or a structure associated with it (e.g., the spacer). Asa result of the force, the one or more bend plates may plasticallydeform. For example, it may deform without plastic elongation, withoutplastic compaction, without plastic buckling or any combination thereof.The forward end of the column housing may remain fixed in place, orotherwise be limited in the extent of forward travel (e.g., in an amountof less than about 50 mm, 20 mm or 10 mm). In addition, by the releaseof the structure applying a clamping or other securing force for theinner column tube (e.g., by release of the breakaway insert from thetilt bracket), clamping or other securing forces for (e.g., those causedby the column housing) the inner column tube will be released and willallow the inner column tube to translate forward as well.

In general, the teachings herein envision a steering column assemblythat employs a column housing with an inner column tube. The teachingsare not limited solely to such assemblies. The teachings also havegeneral application to other types of steering column assemblies.Without limitation, for example, the teachings are also contemplated foruse with a steering column assembly that is known typically as atranslating column type assembly. Such an assembly may integrate acolumn housing with an inner column tube. Such integration may be in theform of a single fabricated unit (e.g., a casting). The unit may bemounted within a vehicle. It may be mounted by way of one or more pinsin one or more slots. An energy absorption unit may be employed as well.During a secondary impact, the unit may travel forward along with a tiltlever, or in the absence of a tilt lever.

Put another way, by way of summary (without limitation) of the generalteachings herein, in a general respect, the present teachings relate toa collapsing steering column assembly. The assembly includes a steeringshaft support structure. For example, it may include a column housing,which may have one or more of the features as described in the presentteachings. It may include an inner column tube which may have one ormore of the features as described in the present teachings and beingadapted for telescopic adjustment within the column housing. It maysimply be a tube or other suitable hollow structure (e.g., the singlefabricated unit integrated structure referenced above) for receiving asteering shaft. A steering shaft, which may have one or more of thefeatures as described in the present teachings (which may support asteering wheel that is attached to it in part and may optionally be apart of the assembly), may be supported for rotation (e.g., by one ormore bearings), at least in part by the steering shaft support structureand having a longitudinal axis. A bracket, which may have one or morefeatures as described in the present teachings, may be employed for atleast partially carrying the steering shaft support structure andattaching the assembly within a vehicle (e.g., to a cross-vehiclestructure). For example, as described, the bracket may include a portionthat provides a guide structure along one or more downwardly projectingwalls for allowing tilt adjustment. At least one securing member, whichmay have one or more of the features as described in the presentteachings (e.g., a tilt bolt, in the case of a tilt adjustable steeringcolumn assembly), may be employed for fixing the position of thesteering shaft support structure relative to the bracket. For example,the at least one securing member may be operatively connected to anactuator or other user operating device (such as a lever orelectromagnetic actuator). The at least one securing member may beoperated to apply a force state (e.g., a clamping force) to help securethe steering shaft support structure in a fixed position. The assemblymay include at least one breakaway structure associated with thebracket, the at least one securing member, or both. The at least onebreakaway structure may have one or more of the features as described inthe present teachings. The at least one securing member may beconfigured relative to the at least one breakaway structure in a mannersuch that in an event of an impact (e.g., a secondary impact) exceedinga threshold load, at least a portion of the at least one securing memberbreaks away from a secure engagement position by way of the at least onebreakaway structure and allows the steering shaft support structure totranslate forward (e.g., in a collapse stroke). The threshold load maybe a load of about 0.5 kN or more, or about 2 kN or more. The thresholdload may be a load of about 10 kN or less, or about 5 kN or less. Thethreshold load may be based on a customer's specified load requirements,which is typically between about 2 kN and about 5 kN. There may also beemployed one or more energy absorption devices that are operable toabsorb energy in response to a force applied to it at least partiallydue to the forward translation of the at least one securing member. Forexample, a bend plate, a wire, or the like, may be in operativeengagement with the at least one securing member and with the steeringshaft support structure so that energy is absorbed by way of plasticdeformation of the energy absorption device. The energy absorptiondevice may be operatively engaged by the at least one securing member inan event of an impact (such as a secondary impact) exceeding a thresholdload. The securing member (e.g., a tilt bolt) may travel forward and maycause the energy absorption device to deform (e.g., plastically) so thatenergy from the impact is absorbed by virtue of the deformation.

Turning now to the drawings to provide one illustrative example of theteachings herein, reference is made first to FIGS. 1 and 2. FIG. 1illustrates an assembly 10 that includes a steering shaft 12 having arearward end portion 14 and a forward end portion 16. A key lock collar18 is located toward the forward end portion. An inner column tube 20 ispositioned toward the rear of the assembly, and is at least partiallydisposed in a forward facing column housing 22. The column housing has afixed pivot location 24 that is closed except for a transversecylindrical opening 26 to receive mounting hardware. The column housingmay include a longitudinal opening 28. One function of the opening is tobisect the wall of the column housing that surrounds the inner columntube 20 so that bisected portions can be moved toward and away from eachother to achieve clamping of the inner column tube 20. The columnhousing may have an arm 30 or other structure to receive and/or carry abiasing device 32 (e.g., a spring). The column housing may also includea suitable carrier 34 for any energy absorption device (e.g., plates36).

A tilt bracket 38 has an upper wall 40 and projecting side walls 42. Thebiasing device 32 is connected to the tilt bracket 38 (e.g., via theupper wall 40).

The inner column tube may carry a plate stop device 44.

Actuation and adjustment of the assembly may be achieved by way of anadjustment subassembly 46. The adjustment subassembly may include alever 48, and an elongated fastener (e.g., a tilt bolt) 50 may passthrough the lever. A cam assembly may be employed. For example, a cammove 52 may be associated with the lever, and may oppose a cam fix 54.As seen in more detail in FIG. 3, breakaway insert 56 having anelongated slot 58, a tapered wall 60, and optionally a groove 62 ispositioned between the lever and a spacer 64. In the embodiment shown,see FIG. 4, the spacer 64 has a hollow elongated shaft 66, and anenlarged head 68. The enlarged head (which may have one or more flatsurfaces, e.g., upper and lower surfaces) has outwardly projectingshareable tabs 70 adapted to be inserted matingly into slots associatedwith the column housing to fix the position of the spacer, such as isseen in FIG. 6b . In the event of a secondary impact, the tabs can besheared allowing the spacer to slide longitudinally. The shaft 66 has anend portion 72.

The subassembly further includes as an engagement member a cam lock 74that optionally includes teeth on an engaging surface. The engagementmember can be biased, such as by a coil spring 76.

In the illustrative embodiment shown, breakaway inserts are on opposingsides of the assembly, as are the spacers. The fastener connects theelements together and is fastened in place with a nut 78 (e.g., aplastic nut, such as a nylon nut, with a flange on it) that adjoins asuitable bearing 80 (e.g., a thrust bearing).

The fastener includes a shank portion (which may have one or morelongitudinal flat surfaces) that is positioned beneath a portion of theplate stop device 44, which is illustrated in greater detail in FIG. 5.The plate stop device 44 includes a base portion 82, a bridge portion 84(beneath which the fastener (e.g., its shank) is located) with a lateralflange 86, an elongated slot portion 88 (in which the engagement memberis located). Soft stoppers 90 (e.g., elastic stoppers) may be locatedtoward the end of the bridge portions. The end portion 72 of the shaft66 may reside at least partially beneath the bridge portion 84 of theplate stop (e.g., below a lateral flange 86) for resisting column lash,as seen in FIG. 6 b.

As seen in FIGS. 6a and 6b , one or both side walls 42 of the tiltbracket 38 has an opening 92 that receives the breakaway insert 56.Though other shapes can be employed the structure of the side wall 42opening has a generally complementary shape as the outer portion of thebreakaway insert. Thus it is possible that the breakaway insert 56 cannestingly reside within the side wall during normal operation. The sidewall may include a tapered wall portion 94 that generally opposes thetapered wall 60 (see FIG. 3) of the breakaway insert.

With reference to FIGS. 7a, 7b, 8a and 8b , it can be seen how during acollapse stroke (depicted in FIGS. 7b and 8b ) both the inner columntube 20 and the lever 48 translate forward, and away from the vehicleuser. In such instance, when a threshold stress is realized, the tabs 70(see FIG. 4) of the spacer shear and cause the fastener to urge thebreakaway inserts 56 forward. As the breakaway inserts move forward,they will release and become disengaged from the tilt bracket, and willthus allow the column housing to release its clamping force upon theinner column tube. Due to the tapered portion 60 (see FIG. 3) of thebreakaway insert, the tapered wall portion 94 (see FIG. 6b ) of the topbracket side wall, or both, it is possible that the breakaway insertwill allow releasing of the clamping force before the entirety of thelength of the breakaway insert has translated in a forward direction. Asseen, by virtue of the unique combination of elements, the subassemblythus translates forward and away from the user. Meanwhile, the columnhousing will remain in place (and will not become disengaged) at itsfixed pivot location 24. Moreover, if bend plates 36 are employed, theymay plastically deform for absorbing energy such as is taught inPublished U.S. Application 2013/0233117, the entirety of which isincorporated by reference herein for all purposes. For instance they maybe carried by the carrier 34 (see FIGS. 1, 2, 6 a and 6 b) of the columnhousing and deform around the spacer 64 (see FIG. 4).

FIGS. 9a and 9b illustrate examples of how tilt brackets 38′ and 38″ ofthe teachings herein can be modified to provide a breakaway structure.The brackets 38′ and 38′ respectively each have an upper wall 40′ and40′, and projecting side walls 42′ and 42′, akin to the embodimentspreviously described. However, in these embodiments, instead of abreakaway insert, the side walls are configured to define one or morestress concentrators. Thus in the event of a secondary impact, anelongated fastener or other securing member (e.g., tilt bolt) 50′ and50″ located at least partially in an elongated slot 58′ and 58″ cause aportion of the side walls to rupture so that breakaway can occur. Forexample, in FIG. 9a , a notch A′ defining a thinned portion(substantially juxtaposed with the notch A′) is shown. The side wallstructure (e.g., a rearward portion of the sidewall structure) may thusbe structured to allow a portion of the side wall 42′ (in the drawingshown, a lower portion) to break away from another fixed portion. Theelongated fastener or other securing member may thus be retained in thebroken away portion. In FIG. 9b , a thinned forward wall section A″ isshown. Also shown in in FIG. 9b is an optional notch in a forward facingportion of the side wall 42′. One or more of such a notch or some otherlike structure may assist in defining one or more stress concentratorsfor helping to control rupture of the forward portion of the side wallfor allowing the elongated fastener to break away from the side wall. Acombination of some or all of the features of each of FIGS. 9a and 9bmay be employed.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

As can be appreciated, variations in the above teachings may beemployed. For example, it may be possible to make the steering wheeladjustment subassembly from multiple subassemblies. A fastener forapplying clamping to the inner column tube via a cam may be separatefrom a fastener to which the breakaway inserts are secured. A structurefor receiving the breakaway insert need not necessarily be a cut-outrelative to side wall of the tilt bracket. A tilt positive locking platemay engage teeth on a forward portion of the tilt bracket when breakawayhas occurred. The energy absorption mechanism described may besubstituted with some other mechanism. For example, an energy absorptionmechanism may be secured to the inner column tube such that it slideswith the tube and is locked to the housing via a cam driven by the tiltlever. Clamping of the inner column tube may be due to application offorce from the tilt bracket (e.g., from outward projecting walls of thetilt bracket) in the absence of force from an intermediate columnhousing. Though the teachings herein may reference to a secondary impactevents as occasioning certain of the functional aspects of theteachings, the teachings are not solely limited to secondary impactevents. Rather, where reference is made to secondary impact, unlessotherwise qualified, the teachings should be regarded as contemplatingother impacts or conditions in which a threshold load (e.g., in aforward facing direction in a vehicle) is encountered that substantiallyexceeds a normal operational load and where a breakaway event may bedesirable for substantially reducing load that otherwise would betransferred to a vehicle operator.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time and the like is, for example, from 1 to 90,preferably from 20 to 80, more preferably from 30 to 70, it is intendedthat values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. areexpressly enumerated in this specification. For values which are lessthan one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate. These are only examples of what is specifically intendedand all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application in a similar manner.

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints. The use of “about” or “approximately” inconnection with a range applies to both ends of the range. Thus, “about20 to 30” is intended to cover “about 20 to about 30”, inclusive of atleast the specified endpoints.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. The term “consisting essentially of” to describe a combinationshall include the elements, ingredients, components or steps identified,and such other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination. The use of the terms “comprising” or “including” todescribe combinations of elements, ingredients, components or stepsherein also contemplates embodiments that consist essentially of, oreven consisting of, the elements, ingredients, components or steps.

Plural elements, ingredients, components or steps can be provided by asingle integrated element, ingredient, component or step. Alternatively,a single integrated element, ingredient, component or step might bedivided into separate plural elements, ingredients, components or steps.The disclosure of “a” or “one” to describe an element, ingredient,component or step is not intended to foreclose additional elements,ingredients, components or steps.

Relative positional relationships of elements depicted in the drawingsare part of the teachings herein, even if not verbally described.Further, geometries shown in the drawings (though not intended to belimiting) are also within the scope of the teachings, even if notverbally described.

What is claimed is: 1) A collapsing steering column assembly comprising:a) a steering shaft support structure; b) a steering shaft that issupported for rotation at least in part by the steering shaft supportstructure and having a longitudinal axis; c) a bracket for at leastpartially carrying the steering shaft support structure and attachingthe assembly within a vehicle; d) a securing member for fixing a secureengagement position of the steering shaft support structure relative tothe bracket; and e) a breakaway structure associated with the bracket,the securing member, or both; wherein the securing member is configuredrelative to the breakaway structure in a manner such that in an event ofan impact exceeding a threshold load, at least a portion of the securingmember breaks away from the secure engagement position by way of thebreakaway structure and allows at least a portion of the steering shaftsupport structure, at least a portion of the securing member that breaksaway, or both to translate forward. 2) The assembly of claim 1, whereinthe steering shaft support structure includes an inner column tube and acolumn housing, wherein the inner column tube is configured fortelescoping insertion within the column housing. 3) The assembly ofclaim 2, wherein the securing member applies a clamping force forsecuring the column housing to the inner column tube by way of a lever.4) The assembly of claim 1, wherein the assembly includes a manuallyoperated steering wheel adjustment subassembly adapted for: a)selectively adjusting the steering shaft in a fore or aft directiongenerally along the longitudinal axis; b) selectively raising orlowering the steering shaft; or c) both a) and b); wherein the steeringwheel adjustment subassembly includes a lever for manually actuating thesteering wheel adjustment subassembly. 5) The assembly of claim 1,wherein the bracket includes a pair of generally opposing downwardlyoriented walls that flank at least a portion of the steering shaftsupport structure; and wherein the breakaway structure includes at leastone breakaway insert that is operatively attached with at least one ofthe downwardly oriented walls in a normal operating position. 6) Theassembly of claim 5, wherein one or both of the downwardly orientedwalls includes a forward facing cut-out to receive the at least onebreakaway insert, and wherein the at least one breakaway insert has alength and includes a tapered portion that tapers from a forward portiontoward a rearward portion and has an elongated slot adapted to receivethe securing member. 7) The assembly of claim 1, wherein an energyabsorption device is adapted to be carried at least partially by thesteering shaft support structure and employed for absorbing energy byway of plastic deformation of the energy absorption device during theforward translation of the steering shaft support structure. 8) Theassembly of claim 1, wherein at least a portion of the steering shaftsupport structure is pivotally mounted at a forward end of the steeringshaft support structure within an automotive vehicle. 9) The assembly ofclaim 1, wherein the securing member includes a tilt bolt. 10) Theassembly of claim 1, wherein the steering shaft supports a steeringwheel. 11) A collapsing steering column assembly, comprising: a) aninner column tube; b) a steering shaft that is supported for rotation atleast in part by the inner column tube and having a longitudinal axis;c) a bracket for carrying the inner column tube and attaching theassembly within a vehicle; d) a column housing, wherein the columnhousing and the inner column tube each have a longitudinal axis; e) asecuring member for fixing the position of the inner column tuberelative to the column housing by way of the securing member thatapplies a force to at least one of the column housing or inner columntube for causing a secure engagement of the inner column tube and thecolumn housing; and f) a breakaway structure; wherein the securingmember is configured relative to the breakaway structure in a mannersuch that in an event of an impact exceeding a threshold load, thesecuring member breaks away from a secure engagement position by way ofthe breakaway structure and allows the inner column tube to translateforward relative to the column housing. 12) The assembly of claim 11,wherein the assembly includes a longitudinally slotted plate stop deviceattached to the inner column tube and including one or more baseportions at each of its forward end and rearward end portions andopposing side walls that project upward from the one or more baseportions and include longitudinally extending side slots adapted toreceive the securing member. 13) The assembly of claim 11, wherein thecolumn housing is pivotally mounted at a forward end of the columnhousing within an automotive vehicle. 14) The assembly of claim 11,wherein the bracket includes a pair of generally opposing downwardlyoriented walls that flank either or both of at least a portion of theinner column tube or the column housing; and wherein the breakawaystructure includes at least one breakaway insert that is operativelyattached with at least one of the downwardly oriented walls when theinner column tube, column housing, or both, are in the secure engagementposition. 15) The assembly of claim 11, wherein the assembly includes atleast one plastically deformable energy absorption device adapted to becarried at least partially by the column housing, wherein the energyabsorption device, when employed, absorbs energy by plastic deformationduring the impact after the inner column tube starts to translate alongthe column housing. 16) The assembly of claim 15, wherein the securingmember is at least partially surrounded by a spacer, and wherein thespacer includes a first portion adapted to oppose the energy absorptiondevice and allow for sliding engagement with the energy absorptiondevice during the impact. 17) A collapsing steering column assembly foran automotive vehicle, comprising: a) an inner column tube; b) asteering shaft supported for rotation at least in part by the innercolumn tube and having a longitudinal axis, c) a tilt bracket adaptedfor receiving at least a portion of the inner column tube and formounting the steering column assembly within the automotive vehicle, thetilt bracket including a pair of opposing side walls; d) a manuallyoperated steering wheel adjustment subassembly adapted for: i)selectively adjusting the steering shaft in a fore or aft directiongenerally along the longitudinal axis, ii) selectively raising orlowering the steering shaft; or iii) both i) and ii), the steering wheeladjustment subassembly including a lever adapted for manually actuatingthe steering wheel adjustment subassembly, at least one engagementmember that is brought into and out of engagement with the inner columntube for selectively locking the steering shaft into a position desiredby a user, at least one breakaway insert that detachably mounts thesteering wheel adjustment subassembly relative to the tilt bracket, anda fastener assembly that operatively connects the lever, the at leastone engagement member and the at least one breakaway insert; e) a columnhousing that is pivotally mounted at a pivot mounting location withinthe automotive vehicle and that at least partially surrounds the innercolumn tube to permit steering shaft adjustment by way of the steeringwheel adjustment subassembly, the column housing including an elongatedlongitudinally oriented opening that defines opposing inner wallsurfaces that are urged toward the inner column tube for clamping theinner column tube into position using the lever, the inner column tubebeing clampable in position relative to the column housing, the tiltbracket, or both; wherein during a secondary impact, the column housingoptionally remains in a generally fixed position relative to the pivotmounting location; wherein at least a portion of the steering wheeladjustment subassembly is adapted to detach from or otherwise becomedisplaced relative to the tilt bracket by way of the at least onebreakaway insert and translate during the secondary impact for movingthe lever away from the user; and wherein upon translation of the atleast one breakaway insert, the inner column tube becomes unclampedrelative to the column housing, the tilt bracket or both; and whereinthe assembly includes at least one plastically deformable energyabsorption device adapted to be carried at least partially by the columnhousing, wherein the energy absorption device, when employed, absorbsenergy by plastic deformation during the secondary impact after thesteering wheel adjustment subassembly starts to translate along thecolumn housing. 18) The assembly of claim 17, wherein one or both of theopposing side walls of the tilt bracket has a forward facing cut-outconfigured to receive the at least one breakaway insert, the forwardfacing cut-out being generally c-shaped to receive the at least onebreakaway insert; wherein the at least one breakaway insert has a lengthand includes a tapered portion that tapers from a forward portion towarda rearward portion, and has an elongated slot adapted to receive a tiltbolt of the fastener assembly and allow upward and downward motion ofthe steering shaft relative to the tilt bracket; and wherein duringnormal operation the tapered portion of the at least one breakawayinsert contacts an opposing surface of the tilt bracket and thedimensions of either or both of a taper of the tapered portion or theopposing surface are such that as the secondary impact occurs, the atleast one breakaway insert is able to detach from the column housing toallow the forward translation. 19) The assembly of claim 18, wherein theassembly includes a longitudinally slotted plate stop device disposed inthe elongated longitudinally oriented opening of the column housing andattached to the inner column tube; and wherein the longitudinallyslotted plate stop device includes one or more base portions at each ofits forward and rearward end portions, opposing side walls that projectupward from the one or more base portions and include longitudinallyextending side slots adapted to receive the tilt bolt, at least onetransversely extending flange on one or more of the opposing side walls,one or more elastic stoppers at terminal locations of the longitudinallyextending side slots, and an upper longitudinal slot adapted to receivethe at least one engagement member. 20) The assembly of claim 19,wherein the tilt bolt is at least partially surrounded by a spacer;wherein the spacer is a hollow, generally cylindrical spacer that has afirst portion adapted to oppose the energy absorption device and allowfor sliding engagement with the energy absorption device during thesecondary impact; a second portion that includes one or more projectionsadapted to be received within the tilt bracket, the column housing, orboth, and that will shear during the secondary impact to allow the tiltbolt to translate forward; and at least a portion of the spacer isdisposed beneath a portion of the slotted plate stop device forresisting column lash.